Emotiva XSP-1 "HT Bypass" and noise through USB...

[archimago]

Hi folks, I unfortunately do not get a chance to visit here much.

I've seen at least another thread commenting on issues with noise heard in "HT Bypass" mode and well as received E-mails about this. It certainly seems the analogue inputs are quite sensitive.

This weekend I put up a post on this on my blog. It turns out I was hearing a bit of noise from ground loops and especially electrical circuit noise through the USB connection to the DAC. Got the recent Corning Optical USB cable and it worked to remove the 8kHz USB "packet noise" as well as the interference from computer processing over the last couple of months. I also used a USB-to-ethernet extender previously that also worked but not as well.

Anyhow, check it out if you're running into issues with the HT Bypass input.

archimago.blogspot.com/2015/05/measurements-corning-usb-3-optical.html

[qdtjni]

Very interesting! 

Were you using an USB3 or USB2 output on your computer?

[archimago]

Hi!

Yeah, it was the USB3 port on the ASUS B85M-E/CSM (+ inexpensive Pentium G3220 CPU) motherboard of the computer in the sound room.

I did try the USB2 port as well which did not make a difference for me. They both were causing that annoying 8kHz tone and processing noise.

Previous to this computer build, I was using an ASUS F2A85-V Pro in combination with an AMD APU processor. Again, noise issues there as well with HT Bypass.

[qdtjni]

So USB 3 is not that much worse than USB 2, at least not in this sense?

Would be interesting to see tests and measurements for a SBT and a Raspberry Pi too.

[archimago]

I do have the SBT so that's a good idea to try.

Will at least give me a sense of relative contamination from the computer's USB port vs. a streaming device. Will give it a try when I have some time :-).